The 10th amendment to the U.S. Constitution states that the powers not delegated to the federal government by the Constitution, nor prohibited by it to the states, are reserved to the states… or to the people. But the Constitution gives Congress broad power to regulate activities that have an effect on interstate commerce. Congress has used this authority to regulate many aspects of American life, from labor relations to education to health care to agricultural production. Since virtually every aspect of the heath care system has an effect on interstate commerce, the power of Congress to regulate health care is essentially unlimited.
I'm sure health care affects interstate commerce in lots of ways, except, oh yeah, for the ability to buy health insurance across state lines.
Nominations for "Most Abused Constitutional Amendment" must start with the Tenth, no? Does any other even come close?